In December 1982, he and Damian Hamada formed Seikima-II. In accordance to their "prophecy" and after completing their "world conquest", the band disbanded at the end of the century on December 31, 1999 at 23:59:59. They have reunited for reunion tours in 2005 and 2010.

He released his first solo work in 1990, and after Seikima-II disbanded focused on his solo career.

In 1994 Demon appeared on Larry King Live, becoming the first Japanese musician to do so.